November 27, 2013

Make Up Your Mind

by Joshua Garrett

Among my friends, the hardest thing to do is get anyone to decide on something, be that where to go for dinner to what movie or what show to watch on Netflix to just about any other normal, simple decision that people have to make every day. Often this is simply attributed to no one wanting to be the one to make a decision at the risk of someone else not being happy with it and not voicing their opinion, but at times we all just seem completely incapable of making up our minds about anything. Considering just how bad this can be sometimes, I am beginning to wonder if the lot of us have a problem with our lateral habenula.

The lateral habenula is the smallest part of the human brain, as well as possibly one of the oldest in terms of evolution, and according to a recent study conducted by researchers at the University of British Columbia, it may be linked to our ability to make decisions. It has been long linked to things like depression and avoidance behavior, but its true purpose may have long been misunderstood. These new findings mark it as a crucial component to our cost-benefit decision making. In the study, lab rats were trained to choose between two different food options. The first consisted of a single food pellet appearing regularly or four food pellets that would be given to them less frequently, varying as needed for the experiment. What this part of the study showed is that rats acted much like humans do given basic economic principles of risk/reward. They more often opted for the larger reward when the costs of said reward – the time they had to wait between being given food – was low and, alternately, preferred the smaller reward when their personal risks were higher. Researchers had assumed that turning off the rats’ lateral habenula would cause the rats to opt for the larger reward, despite the risk, more often but they were surprised to learn that this was not the case. Rather, the rats chose at random, as they were unable to decide which of the two food options would be better for them. According to Professor Stan Floresco of the UBC’s Department of Psychology and Brain Research Center, this could have significant implications for the treatment of depression, saying “ Deep brain stimulation, which is thought to inactivate the lateral habenula, has been reported to improve depressive symptoms in humans, but our findings suggest these improvements may not be because patients feel happier. They may simply no longer care as much about what is making them feel depressed.” Professor Floresco believes that further study is needed to understand all of the brain functions involved in cost/benefit analysis, as such an understanding could help lead us to more successful treatments for such psychiatric disorders as schizophrenia, stimulant abuse, and depression.

The human mind is absolutely incredible. Even now we are learning more and more about the intricate complexities of the brain and just how it works.